Issue 53

J. Akbari et alii, Frattura ed Integrità Strutturale, 53 (2020) 92-105; DOI: 10.3221/IGF-ESIS.53.08

- The entire analyses are nonlinear and the time history analyses are an explicit integral. - Adaptive meshing is used. - FSI is incorporated. - The interaction between the tank and its bottom support is ignored.

The fluid within the tank is generally assumed to be incompressible and non-viscous in the formulation of seismic problems for tanks. As well, the fluid is assumed to be non-rotational. The Laplace differential equation is employed based on the velocity potential function to model the ideal fluid movement. The Laplace boundary conditions are defined by the dynamic response of the tank structure. These boundary conditions are a combination of ground movement-induced vibration and hydrodynamic load-induced deformation.

R ESEARCH M ETHODOLOGY

Validation ue to the complications of the problem, it is required to validate the numerical model before examining the seismic behavior of the tank-fluid model. For this purpose, the study of Maykawa [25], which includes a roofless ground tank-fluid tank, was used. The experimental results included the measurement of the pressure, surface wave height, and shell stress in a time of 8 s by an accelerogram. As can be seen, the system (Fig. 1) is placed on a rigid rectangular plane. D

Figure 1: The physical model of the experimental tank-fluid system [14]

The tank’s height and diameter are both 1.83 m, the tank wall thickness is 2 mm, the tank material is aluminum with an elasticity modulus of 71 GPa, the material density is 2,700 kg/m 3 , and the yield stress is 100 MPa. The fluid is water with a density of 1,000 kg/m 3 in 1.53 m of height. The seismic load is applied by a seismic table with an accelerogram of maximum base acceleration of 0.5 g. Fig. 2 demonstrates the acceleration records in the north- south direction.

Figure 2: The accelerogram of the experimental model [14]

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